This invention relates generally to roll baling machines typically referred to as round balers which form cylindrical roll bales of crop material. In particular, this invention relates to a twine wrapping apparatus for such roll baling machines.
U.S. Pat. No. 4,167,844 discloses a twine wrapping apparatus including a drag link connected between a cam follower link and a driven link. The cam follower link carries a roller engaged with a cam plate, and the driven link is connected to a twine dispensing tube. When the cam plate is rotated, the roller on the cam follower link follows the peripheral contour of the cam plate so that the cam follower link moves the drag link in a manner which results in rotation of the driven link and pivoting movement of the twine dispensing tube. A significant disadvantage of this twine wrapping apparatus is that precise adjustments of the cam plate and the drag link are required in order for the apparatus to operate properly.